Malarial Tablet Resistance

There are some strains of malaria that have become resistant to certain types of medication and therefore some malaria tablets are not effective at treating the disease on their own. Most drugs are given in combinations to eliminate the chance of the parasite surviving so that if the parasite is resistant to one of the drugs, there is another medication that it might not have resistance against.

Plasmodium falciparum has become resistant to Chloroquine since the 1970’s. Chloroquine was a very effective antimalarial and its discovery allowed for the control of malaria in a number of countries. The resistance started in South-East Asia and South America at this time but quickly spread throughout the world as the parasite developed a mechanism to pump the drug out of the cells it was infecting so that it couldn’t cause any damage to the parasite. This is frustrating because this drug was a very cheap, effective way of treating malaria. There has also been some resistance to sulfadoxine-pyrimethene in Asia and South America, which is now spreading to Africa. Clindamycin is the drug that is often prescribed to drug resistant malaria, as the parasite has not formed a resistance to this form of treatment.


Plasmodium falciparum is the most likely parasite to develop resistance and it has been quite problematic to solve. New antimalarial drugs are constantly being developed but are either not as effective as Chloroquine or they have adverse side effects.  Resistance to other anti-malarials has also started to appear in certain parts of the world. Artemisinins resistance has been reported in Thailand in 2009 due to the lack of combination drugs used and patients failing to take the full course of the medication. There is also some resistance to Mefloquine in Thailand.

How is resistance prevented?

In order to reduce the amount of resistance that is occurring to malaria tablets, there are a number of things that authorities can do.  One is to make sure that anti-malarial are not used for non-malarial problems. The less the drug is exposed to the environment, the less chance of resistance. Therefore, if malaria is uncomplicated and does not have any resistance, conventional drugs should be used so that the drugs that do not have any resistance are not placed into circulation too often. Medical authorities can also try to ensure that the full course of malarial tablets is taken by patients to reduce the chance of resistance.

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